iOS 4.0 Emergency: Please help regarding iphone 3gs 4.0 update

Guys please answer this question:
My bro who living in UK has iphone 3gs (not jail-broken) purchased 2 months back, now he will be returning to India permanently in next 2days, now he wants to Jailbreak it....shud i tell him to upgrade it and bring it here in India n then jailbreak? or shud i tell him not to upgrade?

please please reply only 1day is left for his departure from London to India